feat: add admin routes, summarizer service, and CLI summarize command

- Add /admin routes for manual trigger and status inspection
- Add summarizer service with batch/single summary support
- Add summarize CLI command (single arxiv_id or batch pending)
- Register admin router in main app
- Add tests for summarizer

app/routes/admin.py

@@ -0,0 +1,48 @@
+"""管理接口 — AI 总结触发，需要 ADMIN_TOKEN 鉴权。"""
+
+from __future__ import annotations
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
+from sqlalchemy.orm import Session
+
+from app.config import settings
+from app.database import get_db
+from app.services.summarizer import summarize_batch, summarize_single
+
+router = APIRouter(prefix="/admin", tags=["admin"])
+security = HTTPBearer()
+
+
+async def verify_admin(
+    credentials: HTTPAuthorizationCredentials = Depends(security),
+) -> str:
+    """验证 ADMIN_TOKEN。"""
+    if credentials.credentials != settings.ADMIN_TOKEN:
+        raise HTTPException(status_code=401, detail="Invalid admin token")
+    return credentials.credentials
+
+
+@router.post("/summarize")
+async def admin_summarize_batch(
+    _admin: str = Depends(verify_admin),
+    db: Session = Depends(get_db),
+):
+    """批量总结所有 pending 论文。"""
+    result = await summarize_batch(db)
+    if result.get("status") == "conflict":
+        raise HTTPException(status_code=409, detail=result.get("error", "batch already running"))
+    return result
+
+
+@router.post("/summarize/{arxiv_id}")
+async def admin_summarize_single(
+    arxiv_id: str,
+    _admin: str = Depends(verify_admin),
+    db: Session = Depends(get_db),
+):
+    """总结或重跑单篇论文。"""
+    result = await summarize_single(db, arxiv_id, force=True)
+    if result.get("status") == "not_found":
+        raise HTTPException(status_code=404, detail=f"Paper not found: {arxiv_id}")
+    return result